The typical asking rate per listing is in the $10's per square foot per year. The Newark submarket is going through a decline in rates. In the last 3 months, the median rate fell $6 per sqft per year. That's a 29% decrease in rent.
In the last 90 days, 2 listings have been posted online, which means spaces might be leasing quickly. You'll want to be prepared to make an offer immediately. About 50% of the available leases in the Newark are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,250 sqft. Most buildings in this market are close to 1 stories. Most buildings in this area were built in 1990 and are Class B.